How can I the grab frequency of a me humming?

Ill start off by saying Im very new to working with embedded systems and do not have much experience at all, so if I ask kind of a dumb question, at least you'll know why

So I am working with the DEMOACKIT from Freescale, with the MCF51AC256.

If I was to hum into a microphone, how could I go about getting the frequency of that hum? I'm pretty sure I'll need to make use of a FIR filter but have never even heard of one before I wanted to do this.

Any help would be greatly appreciated. Again, please excuse my noviceness, I'm learning!

Well, I suppose you could do a Fourier transform on a reasonably-sized sample of the hum. Then you could analyze the resulting spectrum and find the lowest-frequency component. That would be the frequency of your hum.

Well I was actually thinking I could use a microphone, amplify it a lot, use a bandpass filter, and when I input it into the processor I would just count the number of zero passes in a given amount of time and that would be my frequency.

So counting the number of zero passes definitely wouldn't work? Thats a shame, I was hoping it would be that easy...

Now, how exactly would I perform a Fourier Transform on the incoming signal? Is the Fourier transform all software that I would write? Is there some sort of bean that I should download for this to work? Or would the signal just be going into a AD converter and I would analyze it from there?

Again, sorry for the novice questions but this is all new to me and I'm i the process of learning all of this right now.